Case Interview Cheat Sheet: Frameworks, Formulas & PDF (2026)

A case interview cheat sheet in 2026 is a condensed reference of the seven core frameworks (profitability, market entry, M&A, pricing, 3Cs, 4Ps, and Porter's Five Forces), the 12 math formulas interviewers test, and the mental math shortcuts that make calculations fast under pressure. The point is quick recall during preparation, not a script: according to IGotAnOffer, McKinsey, BCG, and Bain all penalize candidates who recite a framework verbatim, so use these building blocks to assemble a custom structure for each prompt rather than forcing every case into a template. You cannot bring notes into a live interview, which means the real goal is to internalize the sheet until recall is automatic. Use this page for fast reference, then turn it into reps with the free consulting case book PDFs and timed case math drills, because reading the frameworks and producing them out loud under time pressure are different skills.

Case Interview Cheat Sheet: Quick Path

The 7 Core Frameworks

Every case can be structured using elements from these frameworks. The key word is "elements": build a custom structure for each case using relevant building blocks, never apply any framework verbatim. McKinsey, BCG, and Bain all penalize framework recitation (Source: IGotAnOffer 2025).

Profitability is the most common type. Equation: Profit = Revenue - Costs. Break revenue into Price x Quantity by segment; costs into Fixed + Variable. Key diagnostic: is this industry-wide or company-specific?

Porter's Five Forces measures industry attractiveness. High supplier/buyer power, substitutes, new entrants, or rivalry reduce profitability.

Before moving to formulas, practice matching a prompt to the right framework and question, since that choice sets up everything else.

The 12 Essential Math Formulas

These formulas appear repeatedly across case interviews. You must apply each from memory without a calculator. Every profitability case uses the first three; break-even and contribution margin appear in market entry and pricing cases.

Three of those formulas carry most of the arithmetic in a live case, so run them under a timer before you read the worked example.

Quick Math

1. A segment books $5M of revenue against $3.5M of costs. What is the profit margin, in percent?

   Profit margin = (Revenue - Costs) / Revenue x 100. Quote the percentage, not the dollars of profit.

2. Fixed costs are $900,000, price is $75 and variable cost is $45 per unit. How many whole units break even?

   Contribution margin = Price - Variable cost. Break-even units = Fixed costs / Contribution margin; dividing by price understates it.

3. A $360,000 investment returns $90,000 of cash a year. What is the payback period, in years?

   Payback period = Investment / Annual cash flow. Payback ignores everything after the recovery point, so pair it with a return measure.

Worked Example: Multiple Formulas Applied

Scenario: A SaaS company charges $200/month per user with 50,000 users. Variable cost: $60/user. Fixed costs: $4.2M/month. They consider a price decrease to $180, estimated to increase users by 20%.

Current state:

• Revenue = $200 x 50,000 = $10M/month
• Profit = $10M - ($60 x 50,000) - $4.2M = $2.8M/month

New scenario:

• Users = 50,000 x 1.20 = 60,000
• Revenue = $180 x 60,000 = $10.8M/month
• Profit = $10.8M - ($60 x 60,000) - $4.2M = $3.0M/month

Verdict: Profit increases $200K/month (+7.1%). The 20% volume increase more than offsets the 10% price reduction. Contribution margin check: extra 10,000 users x $120 = $1.2M exceeds margin loss on existing users of 50,000 x $20 = $1.0M.

Now build the same bridge on a different product, graded step by step.

Quick Math

1. A SaaS product charges $150 a month to 80,000 users. What is monthly revenue, in dollars? Answer in $M.

   Revenue = Price x Quantity.

2. Variable cost is $45 per user and fixed costs are $5.4M a month. Using the $12M revenue figure, what is current monthly profit, in dollars?

   Profit = Revenue - Variable cost - Fixed cost, where variable cost = Cost per unit x Quantity.

3. Price drops to $135 and users rise 25% to 100,000. Variable cost stays $45 per user and fixed costs stay $5.4M. What is the new monthly profit, in dollars?

   Rebuild the whole bridge at the new price and volume: Revenue = New price x New quantity, then subtract the new variable cost and the unchanged fixed cost.

Mental Math Shortcuts

No calculators allowed in case interviews. These shortcuts make math fast and reliable under pressure. Practice daily for 2 weeks until each technique is automatic (Source: Hacking the Case Interview 2025).

For the full guide, see mental math for case interviews.

These shortcuts only help when they are automatic, so run three of them against the clock.

Quick Math

1. Using the multiply-by-5 shortcut (divide by 2, add a zero), what is 1,260 x 5?

   Multiply by 5 = halve the number, then add a zero.

2. Using the percentage-combination shortcut (combine 10% and 5%), what is 15% of $7,800?

   Build 15% from a 10% block plus half of that for the extra 5%.

3. Using the divide-by-8 shortcut (halve three times), what is $15,200 divided by 8?

   Divide by 8 = halve the number three times.

Case Structure and Synthesis Templates

Structuring a case (first 60-90 seconds): Restate the question and confirm the objective. Identify 3-4 MECE buckets covering key investigation areas. State which bucket to explore first and why. Verify: no overlap between buckets, nothing important missing. See our MECE principle guide.

Synthesis (final 30-60 seconds): "I recommend [action]. Three findings support this: [1], [2], [3]. The main risk is [risk], mitigated by [action]. Next step: [action]." See our synthesis guide.

Practice building the synthesis template into a full closing statement before you sit a live case.

Common Mistakes to Avoid

Reciting a framework verbatim is penalized at McKinsey, BCG, and Bain: build custom structures using framework elements as building blocks. Jumping to math before understanding the problem wastes time on the wrong question. Calculating silently prevents the interviewer from following your logic and correcting errors.

Forgetting to sanity-check catches errors before the interviewer does: if a coffee shop's annual revenue calculates to $50M, something is wrong. Giving recommendations without data support ("I think they should enter the market") scores poorly.

Related Guides

• Case interview frameworks complete guide: deep dive into all frameworks with examples
• Consulting math formulas: extended formula list with worked examples
• Case interview math practice: timed drills for every formula
• Mental math for case interviews: speed techniques beyond this sheet
• MECE principle explained: the organizing principle behind every framework
• Case interview opening statement: how to present your structure in 90 seconds
• Case interview tips and mistakes: errors that eliminate candidates

How to Drill the Cheat Sheet

Sources (checked June 29, 2026)

• Hacking the Case Interview frameworks guide: https://www.hackingthecaseinterview.com/pages/case-interview-frameworks
• Hacking the Case Interview cheat sheet and study guide: https://www.hackingthecaseinterview.com/pages/case-interview-cheat-sheet-study-guide
• Hacking the Case Interview 26 essential formulas: https://www.hackingthecaseinterview.com/pages/case-interview-formulas
• Management Consulted case interview formulas: https://managementconsulted.com/case-interview-formulas/
• IGotAnOffer case interview frameworks guide: https://igotanoffer.com/blogs/mckinsey-case-interview-blog/118288068-case-interviews-frameworks-comprehensive-guide
• IGotAnOffer case interview math guide: https://igotanoffer.com/blogs/mckinsey-case-interview-blog/case-interview-maths